It is always a pleasure to see the Kopps-Etchells Effect in such perfect form. The sparks from this U.S. Marines helicopter form a starry ring around the edge of the blades—a the result of static electricity created by friction between the dust and the metal blades moving through the air.

From the official U.S. Marines photo caption:

U.S. Marines assigned to Marine Aviation Weapons and Tactics Squadron One (MAWTS-1) break down a rapid ground refueling during the Weapons and Tactics Instructor Course (WTI) near 29 Palms, Calif., March 27, 2015.